1. Technical Field
The present invention relates to a recording apparatus which performs recording on a medium.
2. Related Art
In recent years, in a recording apparatus such as an ink jet type printer, a small-sized recording apparatus which is capable of being carried to outdoor, that is, which is a mobile type, has been spread, in addition to a recording apparatus which is used as a stationary recording apparatus indoor. As to such a mobile type recording apparatus, much further miniaturization is required.
In addition, as to a printer, there is a so-called serial type printer which completes recording by alternately executing a paper transport operation of transporting paper in a predetermined quantity and a recording operation of moving a carriage including a recording head in a paper width direction to record.
Furthermore, as to the ink jet type printer, there are a printer of a type in which a carriage includes an ink cartridge and a printer of a type in which an ink cartridge is provided independently from a carriage and the ink cartridge and the carriage are connected by an ink tube. In both types of serial printers, recording is performed by the carriage reciprocating in a predetermined range.
In the serial type printer, as a configuration of moving the carriage including the recording head in a paper width direction, a configuration in which a driving pulley and a driven pulley which are driven by power of a driving source such as a motor are provided on a frame, an endless belt is put around both pulleys, and the power of the motor is transferred to the carriage through the endless belt to make the carriage reciprocate integrally with the endless belt, has been commonly used.
The driven pulley is biased to an outward direction of a moving region of the carriage and is configured so as to apply tension to the endless belt wound around the driving pulley and the driven pulley.
Since this tension generates shaft loss with respect to a rotating shaft of the driving pulley and the driven pulley, this tension becomes a driving load with respect to the driving source such as the motor.
By the way, a stopper for defining a movement limit position of the carriage is provided at an end part of the moving region of the carriage. This stopper is used, for example, for detecting a current position of the carriage. That is, since a driving current value of the motor increases when the carriage abuts with respect to the stopper, a control portion of the printer can thereby detect that the carriage is at the movement limit position.
On the other hand, in the mobile type small-sized printer as described above or the like, a small-sized motor is also used for driving the driving pulley for miniaturization. However, when the motor for driving the driving pulley is miniaturized, the rating of the motor also decreases, and thus the tension of the endless belt is unable to increase.
When the tension of the endless belt is small, the driven pulley is easily drawn toward the driving pulley side when the carriage abuts on the stopper. As a result, a looseness occurs in the endless belt. This looseness causes a problem such as tooth skipping between the driving pulley and the endless belt.
In doing so, in order to prevent the looseness of the endless belt by the driven pulley being drawn toward the driving pulley side, a recording apparatus including a stopper mechanism for regulating a predetermined movement or more of the driven pulley toward the driving pulley side, is disclosed in JP-A-2006-198936. The stopper mechanism is attached to the frame on which the driving pulley and the driven pulley are provided.
While the stopper mechanism in JP-A-2006-198936 can regulate the movement of the driven pulley toward the driving pulley side, the stopper mechanism is fixed with respect to the wound direction of the belt (a moving direction of the carriage). Since the qualities of material of the frame and the endless belt are usually different from each other, when the printer is placed in a high temperature environment, the amount of expansion of the frame becomes larger than the amount of expansion of the endless belt accompanying the difference of the linear expansion coefficient and thus, the stopper mechanism pushes the driven pulley to the outside of the moving region of the carriage. By doing so, the tension of the endless belt significantly increases and thus, there are some cases of exceeding a load allowed by the motor which is a driving source.